Is a Transcutaneous Electrical Nerve Stimulation (TENS) unit contraindicated in patients with a pacemaker?

TENS Unit Use in Pacemaker Patients

TENS units are not recommended in patients with implantable cardiac defibrillators (ICDs), and should be used with extreme caution—if at all—in pacemaker patients, particularly those who are pacemaker-dependent. 1

Key Distinction: NMES vs. TENS

The evidence clearly differentiates between two types of electrical stimulation:

• Neuromuscular electrical stimulation (NMES) has been found safe in both ICD and pacemaker patients for long-term lower extremity muscle training 1
• TENS units are specifically NOT recommended in ICD patients due to their use of much higher frequencies compared to NMES 1

Risk Profile and Clinical Evidence

Documented Interference Patterns

The risk of interference is real and can be delayed or intermittent:

• Initial testing may be falsely reassuring—one patient showed no interference immediately post-implant but developed pacemaker inhibition causing dizziness and bradycardia six months later with TENS use 2
• Extended cardiac monitoring (Holter monitoring) has revealed pacemaker dysfunction that was not detected on brief electrocardiographic trials during initial TENS application 3
• TENS can cause complete pacemaker inhibition in demand pacemakers, which poses life-threatening risk to pacemaker-dependent patients 4, 3

Specific Risks by Device Type

For pacemaker-dependent patients: Electromagnetic interference can inhibit demand pacemakers, representing a significant mortality risk 4

For ICD patients: TENS has caused inappropriate shocks due to device sensing of the TENS signal as a cardiac arrhythmia 2

Management Algorithm

If TENS is Being Considered (Against Recommendation)

1. Determine pacemaker dependency status first 4, 2

   • If pacemaker-dependent: TENS is contraindicated
   • If ICD present: TENS is contraindicated 1

2. For non-dependent pacemaker patients where TENS is deemed essential:

   • Reprogram device to asynchronous mode if electromagnetic interference is anticipated 4
   • Use only brief bursts of electrical current at the lowest possible amplitude 4
   • Keep TENS electrodes as far from the pacemaker generator as possible 4
   • Perform extended cardiac monitoring (24-hour Holter) during initial TENS use, not just brief ECG monitoring 3
   • Consider reprogramming pacemaker sensitivity if interference detected 3

3. Ongoing monitoring requirements:

   • Even if initial testing is negative, careful follow-up is mandatory as interference can develop over time 2
   • Repeat extended monitoring periodically if TENS use continues 3

Safer Alternatives

Consider pharmacological pain management instead of TENS in all patients with cardiac implantable electronic devices 4

Common Pitfalls to Avoid

• Do not rely on brief ECG monitoring alone—interference may only be detected with extended Holter monitoring 3
• Do not assume initial negative testing means permanent safety—device interaction can develop months after implantation 2
• Do not confuse NMES with TENS—NMES uses lower frequencies and has demonstrated safety, while TENS has not 1
• Beware of ECG artifact—TENS can create electrical spikes on ECG that mimic pacemaker malfunction, leading to misdiagnosis 5

Perioperative Context

In the perioperative setting, the 2024 AHA/ACC guidelines emphasize that electromagnetic interference from various sources (including electrical stimulation devices) can trigger inappropriate ICD therapies or inhibit pacemaker function, requiring device reprogramming or magnet application 1